Will Indalloy™#60 Become the Future of Flexible Electronics?

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One of the first trade shows I attended when I began my career in the electrics industry was an IPC Flexible Circuits Conference in 2006. A decade ago we were talking about advances in flexible electronics – but no one was mentioning stretchableelectronics. Back then, flexible electronics were much more rigid than the electronics we are now looking forward to – they were copper traces on a Mylar (or equivalent) substrate. Flexible electronics are commonplace now.

Recently, scientists at Carnegie Mellon University have been experimenting with a silicone and liquid metal composite material which has some amazing properties. The material is a thermally conductive elastomer. More specifically, it is a silicone material which has pockets of an indium-gallium alloy. This alloy is eutectic indium-gallium (called EGaIn for short) which also goes by “Indalloy™#60” as a trade name. The alloy is 75.5% gallium and 24.5% indium. Because the metal is liquid, it can transfer electricity and heat, while changing form. Here’s a video that will give you a better idea of what’s really going on.

I asked Professor Carmel Majidi for his thoughts on this project, to which he offered: “For the last few years, we’ve been using indium from Indium Corporation to synthesize our liquid metal alloys. We see a lot of potential for using indium for making circuits and multifunctional composites that are deformable and mechanically robust. Thubber is a great example of this — with microscopic droplets of indium-based liquid metal alloys in a soft elastomer, we can engineer a composite that has rubber-like elasticity and metal-like electrical and thermal properties.”